Overview

Even the most powerful furnace can’t do its job without proper insulation and air sealing. Even the coldest AC unit needs a well-insulated area to cool you off on a warm day. Get more out of your heating and cooling and conserve energy with proper insulation and air sealing. Unless your home is brand new - and built by a knowledgeable contractor - you can probably add insulation for a major boost on your home’s energy efficiency.

Home Insulation for your Attic, Basement and Walls

The optimal amount of insulation - whether it’s blown, batt or spray foam insulation - varies according to local climate and the part of the house being insulated (attic, walls or basement). Do-it-yourself insulation and air sealing is difficult to get right: Incomplete coverage and improper air-sealing can seriously compromise the effectiveness of insulation. It may look easy, but unless you’re trained in building science and happy to crawl around in the dust and grime of the furthest reaches of your attic and crawlspace, it’s almost always best to bring in a professional. A professional contractor can determine the optimal amount of insulation depending on your location.

First Step: Attic Insulation

If you have to choose one area for home insulation, choose the attic. Attic insulation is one of the most important and cost-effective projects to get right in your home for optimal comfort and energy efficiency, regardless of local climate. The attic is relatively easy to access and is subject to extreme temperature swings in the winter and summer. For more information on attic insulation, click here.

Exterior Wall Insulation

An exterior wall is any wall that faces outside or otherwise separates your home from the outdoors (including basement walls). These walls should be insulated to create a thermal envelope around your living space. This also includes “knee walls”, which are walls that face an unconditioned indoor space like your attic or garage.

Air Sealing a Cold, Drafty House

Proper air sealing is among the most cost-effective strategies for conserving energy around your home. Protect your home from harsh outdoor temperatures with professionally installed air sealing. Qualified professionals will know that a certain amount of ventilation is necessary to keep air moving.

Unless your house was built in the last five to ten years, there are probably major air leaks in the living space and in the building shell. Older homes can be extremely leaky, which means the hot or cold air that your heater or air conditioner puts out is mostly blowing out of the house. If an older home is sealed too tightly, a mechanical ventilation system - sometimes called an Energy Recovery Ventilator - may be needed to ensure healthy air quality.

After completing an online audit, the first step is to get an in-home energy audit to determine how much air leakage your home currently has and how much of that leakage can be sealed safely to maximize your utility bill savings and minimize your carbon footprint.  

Testing to Reveal Air Leaks

A blower door test is commonly used to determine where any air is leaking in and out of your home. The blower door test starts by depressurizing your home - contractors insert a door with a built in fan that will blow air out your entryway. As the air inside your home is pushed outside through the front door, air from outside of your home will start to seep in through any cracks.  Auditors use colored smoke to make the moving air visible. They will note the areas where air is seeping in during the blower door test so they can come back and seal them up later using foam, caulk or other sealants. The most common problem areas are found on exterior walls or walls that connect to garages, as well as ceilings and floors connecting to attics and crawlspaces. The windows, chimneys, vents, recess lights, attic hatches, electrical outlets and outdoor faucets found on these exterior walls are often high-leakage areas that can be sealed easily. It’s also important to note that air sealing and insulation go hand in hand. If you plan to add insulation to improve the efficiency of your house, be sure to talk with a professional about air sealing at the same time. Without air sealing, your new insulation may be much less effective.

Air Seal and Insulate Your Ducts

If you’ve got a forced air heating or air conditioning system, duct sealing and insulation can significantly reduce your energy consumption. Most homes with unsealed, insulated ducts lose between 10 to 30 percent of the energy used for heating and cooling because the nice warm (or cold) air in their air ducts leaks out before it reaches the living space. In other words, almost a third of what you’re paying to heat or cool your home is wasted before it ever gets to you.

Don’t forget the return ducts as well – many times, return ducts are built into walls. If they are pulling air from outside the home, your furnace and air conditioner’s effectiveness will suffer from any leakage. You’ve got to be careful to seal every junction and seam where there’s leakage - otherwise, the air will just leak out even faster from spots you missed.

Add duct insulation, made of foil or vinyl, after the duct sealing is complete.  If you’d like to find a professional who can help do this for you, we can help you find an expert in your area or check out the Building Performance Institute (BPI) directory of energy efficiency specialists in your area.

Ready to start your project? Click here for useful tips about contractors.